If you are like me, you did not buy the Nike+ model but just got the standard sport model. But I really wanted to get the look of the band that comes with the Nike+ model.
Thankfully there are some great replicas of those bands for super cheap on amazon in a large assorment of colors. I went with the Black and Volt colorway and I love it. The band is created by AdMaster and is available in Both 38mm and 42mm sizes, as well as small and large wrist sizes for each case size.
The air holes in the band allow for better breathability while working out or other activites that would cause your wrist to sweat.
It feels identical to the 1st party silicone Apple Watch bands that you are used too. It uses the same steel buckle for the latch, this allows for little concern for it slipping off your wrist short of wrestling mountain lions.
At the time of writing this post it is available for only $9.90 US. This makes a great cheap alternative to the authentic band.
Buy from Amazon here: https://amzn.to/2uOyRGG